WF in Asp.Net

这几天在研究Windows Workflow Foundation,天天上www.windowsworkflow.net 的论坛上查看和询问，全都是英文，头都看大了，对这金山词霸一个一个的啃。闲话少说，步入正题吧！

本篇主要讲WF在asp.net运用。如下：
我的流程设置如下：

设置了一个CodeActive和一个HandleExternalEventActive
CodeActive是执行一段代码的Active
HandleExternalEventActive是外联一个Event的Active

首先，配置web.config

<!--<br><br>Code highlighting produced by Actipro CodeHighlighter (freeware)<br>http://www.CodeHighlighter.com/<br><br>--><?xml version="1.0"?>
<configuration xmlns="http://schemas.microsoft.com/.NetConfiguration/v2.0">
    <configSections>
        <section name="WorkflowRuntime" type="System.Workflow.Runtime.Configuration.WorkflowRuntimeSection, System.Workflow.Runtime, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
    </configSections>
    <appSettings/>
    <connectionStrings/>
    <system.web>
        <authentication mode="Windows"/>
        <compilation debug="true">
            <assemblies>
                <add assembly="System.Design, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A"/>
                <add assembly="System.Drawing.Design, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A"/>
                <add assembly="System.Transactions, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/>
                <add assembly="System.Workflow.Activities, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
                <add assembly="System.Workflow.ComponentModel, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
                <add assembly="System.Workflow.Runtime, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
                <add assembly="Microsoft.Build.Tasks, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A"/>
                <add assembly="System.Messaging, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A"/>
                <add assembly="System.Runtime.Remoting, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/>
                <add assembly="System.DirectoryServices, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A"/>
                <add assembly="System.Windows.Forms, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/>
                <add assembly="Microsoft.Build.Utilities, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A"/>
                <add assembly="Microsoft.Build.Framework, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A"/>
            </assemblies>
        </compilation>
    </system.web>
  
  <!--注册服务-->
    <WorkflowRuntime Name="WorkflowServiceContainer">
        <Services>
      <add type="System.Workflow.Runtime.Hosting.ManualWorkflowSchedulerService, System.Workflow.Runtime, Version=3.0.00000.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
      <add type="System.Workflow.Activities.ExternalDataExchangeService, System.Workflow.Activities, Version=3.0.00000.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
      <add type="System.Workflow.Runtime.Hosting.SqlWorkflowPersistenceService, System.Workflow.Runtime, Version=3.0.00000.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" UnloadOnIdle="true" ConnectionString="Initial Catalog=PersistenceStore;Data Source=localhost;Integrated Security=SSPI;"/>
      <add type="System.Workflow.Runtime.Tracking.SqlTrackingService, System.Workflow.Runtime, Version=3.0.00000.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" ConnectionString="Initial Catalog=TrackingStore;Data Source=localhost;Integrated Security=SSPI;"/>
    </Services>
    </WorkflowRuntime>

  <!--设置追踪，会在网站根目录下出现WFTrace.log文件-->
  <system.diagnostics>
    <switches>
      <add name="WorkflowTraceToDefault" value="1" />
      <add name="Host" value="All" />
      <add name="Runtime" value="All" />
      <add name="Tracking" value="All" />
      <add name="Activity" value="All" />
      <add name="Rules" value="All" />
    </switches>
    <trace autoflush="true" indentsize="4">
      <listeners>
        <add name="myListener" type="System.Diagnostics.TextWriterTraceListener" initializeData="WFTrace.log" />
      </listeners>
    </trace>
  </system.diagnostics>
</configuration>

简单介绍上面的配置文件
a.注册服务
这里是将一些服务注册到 Workruntime中，你也可以在代码中使用AddServcie中注册服务。
注册好服务后，就可以在代码中
ExternalDataExchangeService dataService = workflowRuntime.GetService<ExternalDataExchangeService>();
以上方式得到服务。
b.跟踪
配置跟踪信息，非常有用，我有一次调试的时候，MSDTC 服务没有启动的错误，就是查看WFTrace.log文件而获得的。

然后,在Global中启动一个WorkRunTime

void Application_Start(object sender, EventArgs e)
    {
        System.Workflow.Runtime.WorkflowRuntime workflowRuntime = new System.Workflow.Runtime.WorkflowRuntime("WorkflowRuntime");
        Application["WorkflowRuntime"] = workflowRuntime;

        System.Workflow.ComponentModel.Compiler.TypeProvider typeProvider = new System.Workflow.ComponentModel.Compiler.TypeProvider(workflowRuntime);
        typeProvider.AddAssembly(typeof(WorkflowLibrary1.Workflow1).Assembly);
        workflowRuntime.AddService(typeProvider);

        workflowRuntime.StartRuntime();
    }

    void Application_End(object sender, EventArgs e)
    {
        System.Workflow.Runtime.WorkflowRuntime workflowRuntime = Application["WorkflowRuntime"] as System.Workflow.Runtime.WorkflowRuntime;
        workflowRuntime.StopRuntime();
    }

接着，就可以在程序中运行workflow了

private void StartWorkflow()
    {
        WorkflowRuntime workflowRuntime = StartRuntime();

        // Now get a refernece to the ManualWorkflowSchedulerService
        ManualWorkflowSchedulerService scheduler =
            workflowRuntime.GetService<ManualWorkflowSchedulerService>();

        // Attach to the WorkflowCompleted event
        workflowRuntime.WorkflowCompleted += new EventHandler<WorkflowCompletedEventArgs>(WorkflowRuntime_WorkflowCompleted);

        WorkflowInstance workflowInstance = workflowRuntime.CreateWorkflow(typeof(WorkflowLibrary1.Workflow1));

        workflowInstance.Start();

        // Now run the workflow.  This is necessary when 
        // using the ManualWorkflowSchedulerService
        scheduler.RunWorkflow(workflowInstance.InstanceId);
    }




    private WorkflowRuntime StartRuntime()
    {
        WorkflowRuntime workflowRuntime = Application["WorkflowRuntime"] as WorkflowRuntime;

        ExternalDataExchangeService dataService = workflowRuntime.GetService<ExternalDataExchangeService>();
        OrderLocalServices.OrderService orderService = workflowRuntime.GetService<OrderLocalServices.OrderService>();

        if (orderService == null)
        {
            orderService = new OrderLocalServices.OrderService();
            dataService.AddService(orderService);
        }

        // Attach to the WorkflowCompleted event
        workflowRuntime.WorkflowCompleted += new EventHandler<WorkflowCompletedEventArgs>(WorkflowRuntime_WorkflowCompleted);
        return workflowRuntime;
    }

最后，运行代码后，当运行完上图中的CodeActive后，该workflowinstance将进入等待状态（会触发workflowRuntinme的WorkflowIdled事件）。
这个时候你如果注册了SqlWorkflowPersistenceService服务，和创建了PersistenceStore数据库，则会将此
工作流保存到数据库中，已备下次使用，关于这块下次我再整理。
为什么工作流会等待了，
因为接下来的环节HandleExternalEventActive的Active必须需要触发了和他相关联的事件后，他才会继续的。
所以，我可以针对workflowRuntinme增加WorkflowIdled事件，实现事件的代码如下：

   void workflowRuntime_WorkflowIdled(object sender, WorkflowEventArgs e)
    {
        
        WorkflowRuntime workflowRuntime = Application["WorkflowRuntime"]  
        OrderService orderService = workflowRuntime.GetService<OrderService>();

        WorkflowInstance instance = workflowRuntime.GetLoadedWorkflows()[0];

        instance.Load();

        //触发相关联的事件
        orderService.RaiseOrderUpdatedEvent(instance.InstanceId);


    }

这样这个工作流就整个的执行完成了。